Abstract
Shell-model calculations using realistic interactions reveal that the ground and low-lying yrast states of the nucleus Pd are mainly built upon isoscalar neutron-proton pairs, each carrying the maximum angular momentum allowed by the shell , which is dominant in this nuclear region. This structure is different from that found in the ground and low-lying yrast states of all other even-even nuclei studied so far. The low-lying spectrum of excited states generated by such correlated neutron-proton pairs has two distinctive features: (i) the levels are almost equidistant at low energies and (ii) the transition probability is approximately constant and strongly selective. This unique mode is shown to replace normal isovector pairing as the dominant coupling scheme in nuclei approaching the doubly magic nucleus Sn.
- Received 20 January 2011
DOI:https://doi.org/10.1103/PhysRevC.84.021301
©2011 American Physical Society